Deuce gear is short for '782 gear' in the Marine Corps. The Army calls it LBE, or Load Bearing Equipment. It is a combination of a harness and pistol belt- ammo pouches, canteens, holsters and various other things are hung on it.
"Deuce gear" is a common term among servicemen. It refers to the form a soldier signs when checking out his equipment from supply, form 782, the 2 being the deuce. It is the soldier's basic equipment, canteen, mess kit, ammo pouches, back pack, etc., and is all included together on this form.
God bless our troops wherever they may be.
it is gear you keep in a deuce bag.